An unknown solution turns blue litmus red and gives a gas with metal carbonate that turns lime water milky. What is the nature of the solution?
Answer and explanation
Correct answer: Acidic
Two independent observations identify the solution as acidic. First, an acid changes blue litmus to red. Second, an acid reacts with a metal carbonate to produce carbon dioxide: acid + carbonate → salt + water + CO2. The gas turns limewater milky because insoluble calcium carbonate forms. A basic or neutral solution would not normally give both of these characteristic tests, and “without nature” is not a scientifically meaningful classification.
Frequently asked questions
What is the correct answer to this question?
Acidic
Why is this the correct answer?
Two independent observations identify the solution as acidic. First, an acid changes blue litmus to red. Second, an acid reacts with a metal carbonate to produce carbon dioxide: acid + carbonate → salt + water + CO2. The gas turns limewater milky because insoluble calcium carbonate forms. A basic or neutral solution would not normally give both of these characteristic tests, and “without nature” is not a scientifically meaningful classification.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
